Global Payments, the electronic transaction-processing firm which acknowledged a data breach in April related to a suspected 1.5 million payment card numbers, yesterday said its ongoing investigation into that is turning up another issue: "potential unauthorized access to servers containing personal information collected from a subset of merchant applicants."

In a statement it put out, Global Payments said, "It is unclear whether the intruders looked at or took any personal information from the Company's systems; however, the Company will notify potentially-affected individuals in the coming days with helpful information and make available credit monitoring and identity protection insurance at no cost."

In a conference call yesterday, CEO Paul Garcia apologized for the ongoing impact of the incident, saying, "We are outraged by these criminal acts." He said the firm is cooperating with federal law enforcement in the investigation.

The firm, based in Atlanta, says its latest discoveries are not related to the cardholder data breach that was uncovered earlier and strictly concern U.S.-based merchant applicants. The company says it doesn't know if the criminals that accessed the servers really looked carefully at the merchant-applicant data or took it.

Garcia said the data-breach incident has caused "certain card brands" - he didn't identify whether it was Visa, MasterCard or any other -- to remove Global Payments from its list of approved providers in terms of Payment Card Industry (PCI) Data Security Standards compliance. Global Payments says it's working on remediation efforts, making changes to its network security, to try and gain PCI DSS compliance approval through a new qualified security assessor that would audit the company's systems. The company said it initially discovered the breach while updating its network.

When asked whether the company thinks more issues will crop up, Garcia said, "We think we're getting to the end of this." The company plans to provide an estimate about the costs of the data breach later in July.

Ellen Messmer is senior editor at Network World, an IDG publication and website, where she covers news and technology trends related to information security.